A city plans to reduce carbon emissions by installing energy-efficient LED streetlights. Each old light used 150 watts, while each new LED uses 60 watts. If the city replaces 800 lights and electricity costs $0.12 per kWh, how much money is saved in one year assuming lights operate 10 hours per day?

Thu, 16 Apr 2026 09:53:23 +0000

**A city plans to reduce carbon emissions by installing energy-efficient LED streetlights. Each old light used 150 watts, while each new LED uses 60 watts. If the city replaces 800 lights and electricity costs $0.12 per kWh, how much money is saved in one year assuming lights operate 10 hours per day?** As cities nationwide shift toward sustainability, energy-efficient upgrades like LED streetlights are emerging as powerful tools to cut emissions—and bring tangible savings to public budgets. With millions of outdated streetlights still in use across the U.S., replacing them not only reduces carbon output but also slashes energy consumption and operation costs. One such initiative centers on an ambitious city project: replacing 800 high-wattage lights with LED alternatives. This transition offers a clear, measurable impact—driving both environmental progress and financial efficiency. ### How this urban LED upgrade delivers real savings At the core of this initiative is the remarkable reduction in power use: replacing each 150-watt light with a 60-watt LED cuts energy demand by 90 watts per fixture. Multiply that across 800 lights, and the total daily energy saved reaches 480,000 watts—equivalent to 480 kilowatts. When lights operate 10 hours a day, annual energy savings amount to 480 kW × 10 hrs × 365 days = 1,752,000 kWh per year. At a grid electricity cost of $0.12 per kilowatt-hour, the financial impact becomes clear: the city saves roughly $210,240 annually. This data illustrates how small-upgrade decisions can generate significant returns—especially in regions balancing infrastructure modernization with climate goals.